Rotary pump.



A. B. KLISE.

ROTARY PUMP.

APPLICATION FILED DI-:c.5,1917.

Patented July 9, 1918.

Jf w i w W Y, I I A III Il ALBERT B. xLIsE,

C0., F PETOSKEY, MICHIGAN,

0F PETOSKEY, MICHIGAN. ASSIGNOR T0 BLACKMER ROTARY PUMP A CORPORATION 0F MICHIGAN.

ROTARY PUMP.

Specification of Letters Patent.

Patented July 9, 1918.

Application led December 5, 1917. SeriaL No. 205,488.

. and useful Improvements in Rotary Pumps,

of which thefollowing is a specification.

My invention relates to rotary pumps particularly to that type in which a piston body rotates within a cylinder and carries with it piston members which reciprocate radially as they travel along the cylinder wall during rotation of the piston body.

The main feature to be covered in this application is an improved pump chamber, more `particularly a cylinder wall of improved curvature. In prior constructions, for example'Blackmer Patent No. 869,050, October 22, 1907, the pump chamber or cylinder' wall engaged by the piston members is formed of wall sections defined by circular arcs of different radius. The disadvantage of this arrangement is that the sections of the walls of different radius do not connect together tangentially but their connecting lines form cusps or ridges over which the piston members must travel, and even before high speed is reached the piston members will tend to bound or clatter causing noisy and inefficient operation. Furthermore the friction is considerable on account'of these cusps, and leakage results.

The feature of my invention is to build up the cylinder wall by curved surface sections which connect tangentially, thus elimihating any sudden radius variation or cusps. I preferably employ two diametrically op; posed circular arcuate sections of different radius and tangentially join the ends of these circular arcuate sections by sections of ellipses, there being a common center for the circular arcuate sections and the'ellipses.

On the accompanying drawing my improved construction is clearly shown. In the drawings- Figure 1 is a side elevational view of a rotary pump with a side wall or cover removed, and

Fig. 2 is a front elevational view, the upper part being in section on plane 2 2, Fig. 1.

The annular body or cylinder frame 10 has the side wall 11 integral therewith, the other side wall 12 being in the form of a detachable cover held in place by screws 13.

A hub 14 extends from the side wall 10 and affords bearing support for the shaft 15 to which the piston body 16 is secured to be rotatable within the cylinder frame 10. At the front of the cylinder frame is the intake frame extension 17 which extends partly around the cylinder frame and is connected with the interior thereof by the port 18. At the top of the cylinder frame is the discharge frame extension 19 which likewise extends partly around the cylinder frame and c onnected with the interior thereof by the port 20. The inner or `cylinder surface of the cylinder frame is designed in accordance with my invention to provide in connection with the piston body the necessary suction and discharge chambers and to form the guiding surface for piston members transported with the piston body. My invention can be utilized in connection with piston structures as disclosed in the patent referred to above or can be utilized with piston structures of other; design. On the drawing I have shown a piston structure which is similar to that described and claimed in my co-pending application executed of even date herewith. This piston structure comprises the piston body 16 hav-- ing thc radially extending spaced `apart pockets 21 for the piston members 22 in the form of rollers and my improved cylinder surface is particularly adaptable in connec-A tion with such piston structure.

Describing now my improved cylinder surface, the section A-B is cylindrical with its center at O which is the center of the shaft 15 and the piston body thereon, the radius of the section A-B being that of the piston body. The arcuate extent of the section A-B is shown somewhat less than 90. Diametrically opposite the section A-B is the arcuate circular section C-D whose center is also at O but whose radius is greater than the radius of A-B. The arcuate extent of the section C-D is greater than 90 and the combined arcuate extent of the sections A-B and C-D is 180. The section B-Co/fdthe cylinder wall `is defined by a quarter section of the ellipse E, whose center is at O. The length of the major axis W-W of the ellipse E is twice the length of the radius of the section C-D, and the length of the minor axis X-X of the ellipse is twice that of the radius of the section A-B, so that the elliptical section B-@G Cit will merge at its ends tangentially into the djaent -ends of `the sections A-B and The remaining section A--AD of the cylinder wall is defined by a quarter section of the ellipse E whose center is at O and whose major and minor axes are of a length such that the ends of the section A-D will connect tangentially with the respective ends of the sections A-B and C-D. Defining the arrangement in other words, t-he major axes of the two ellipses are coincident with the radii passing through the ends of the section C-D, while the minor axes are coincident with the radii extending through the ends of the section A-A-B.

The several sections are so placed with reference to the inlet and outlet ports of the pump that the piston members can operate to draw in charges of fluid at the inlet and discharge the fluid through the outlet port as the piston body is rotated. On account of the smooth tangentially connected together sections of the cylinder Wall the radial shift of the piston members during rotation of the piston body will be gradual, all cusps or sudden variation of radius length being eliminated. There cannot, therefore, be any tendency to pound or elatter, particularly during high speed of the pump and the pump Will operate noiselessly.

- The smooth movement will also reduce friction to a minimum.

I do not, of course, desire to be limited to the exact details shown and described as variations are possible in the designing of the cylinder wall Which would still come within the scope of the invention.

I claim as follows:

1. In a rotary pump of the class described, the combination of a cylinder, a piston body rotatable within the cylinder, piston members carried with said piston body to engage with the cylinder wall,an inlet and an outlet for the cylinder, a section of the cylinder wall having the curvature of a circular arc Whose center is at the center of the piston body and whose radius is equal to that of the piston body, a'section of said cylinder diametrically opposite said first mentioned section having the curvature of a circular arc whose centeris that of the piston body but whose radius is longer than that of the piston body, the remaining sections of said cylinder Wall having the curvature of ellipses whose center is that of the piston body and whose major and minor axes arerespectively twice the lengths of the radii of the larger and smaller circular arc sections.

2. In a rotary pump, the combination of a cylinder having an inlet and an outlet, a piston body rotatable within said cylinder, piston members carried by and shiftable on said piston body yto engage' and coperate with the cylinder walls during rotation of the piston body, a section of said cylinder wall being cylindrical with its center that of the piston body and its radius equal to that` 'of the piston body, the section of said cylinder opposite the first mentioned section being also cylindrical with its center that of the piston body but its radius longer than that of the piston body, the combined arcuate extent of said cylinder sections being 180, the remaining cylinder sections having the curvature of sections of ellipses whose centers are that of the piston body andwhose major and minor aXes are respectively twice the length of the radii of the longer and shorter cylindrical sections of the cylinder wall, said sections of elliptical curvature connecting tangentially with the vends of the cylindrical sections of said cylindrical Wall.

3.A In a rotary pump, the combination of a cylinder having an inlet and an outlet, a piston body rotatable within the cylinder, and piston members shift-able on said'piston body to engage with the cylinder Wall, the cylinder wall surface engaged by said piston members being in part of cylindrical curvature and in part of elliptical curva.- ture, the sections of cylindrical and elliptical curvature being connected together tangentially.

In witness whereof, I hereunto subscribe my name this first day of December, A. D.

ALBERT B. KLISE. 

